320666987 has 2 divisors, whose sum is σ = 320666988. Its totient is φ = 320666986.

The previous prime is 320666977. The next prime is 320667031. The reversal of 320666987 is 789666023.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 320666987 - 2²⁴ = 303889771 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (320666917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160333493 + 160333494.

It is an arithmetic number, because the mean of its divisors is an integer number (160333494).

Almost surely, 2^320666987 is an apocalyptic number.

320666987 is a deficient number, since it is larger than the sum of its proper divisors (1).

320666987 is an equidigital number, since it uses as much as digits as its factorization.

320666987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 653184, while the sum is 47.

The square root of 320666987 is about 17907.1769690256. The cubic root of 320666987 is about 684.4652704317.

The spelling of 320666987 in words is "three hundred twenty million, six hundred sixty-six thousand, nine hundred eighty-seven".